BREITKOPF, brīt'kṓpf, Johann Gottlob Immanuel (1719-94). A German printer and proprietor of a well-known publishing house of Leipzig, established in 1664, and known as Breitkopf & Härtel since 1795. He was born in Leipzig, and graduated from the university of that city. His investigations in history and mathematics led him to a scientific study of printing, which resulted in a more artistic development of German text, and an improvement of musical notation (1754). At the time of Breitkopf, the old form of musical notation had been almost forgotten. Compositions were either written or engraved, and the form of printing music now principally used is undoubtedly due to his initiative. His writings include the following: Ueber die Geschichte der Erfindung derBuchdruekerkunst (Leipzig, 1779); Ueber den Druckder geographischen Karten (3 parts, Leipzig, 1777-79).